internal error reported

I get the following error message:

darcs: internal error: EVACUATED object entered!
    Please report this as a bug to glasgow-haskell-bugs@xxxxxxxxxxx,
    or http://www.sourceforge.net/projects/ghc/

I'm not sure what is causing this.  This is using ghc 6.2, the debian
version that just moved into sarge.  The situation that triggers this (and
I think I've reproduced it twice, so I'm optimistic that it may be
reproducible) is rather complex, so hints as to how to track this down are
probably the best approach (as opposed to creating a simple test case,
which seems a bit unlikely).

I haven't yet tried this same code with an older (or newer) ghc, so I don't
know if this is a new problem.   The test case as it currently exists takes
sever hours of thrashing to disk before crashing.  I may be able to improve
the time to crash dramatically, but am on vacation now and am not sure when
I'll have time to work more on this.
-- 
David Roundy
http://civet.berkeley.edu/droundy/